Hello Monks, I'm having trouble writing cross platform code (win and unix) to detect if a port is in use.

the following subroutine seems to cause this message (on Windows) "Terminating on signal SIGALRM(14)" when the calling code exits. 
sub portAlive {
    my $proto = getprotobyname('tcp');
    my $iaddr = inet_aton($host);
    my $paddr = sockaddr_in($port, $iaddr);
    
    socket(SOCKET, PF_INET, SOCK_STREAM, $proto) || warn "socket: $!";
    
    eval {
      local $SIG{ALRM} = sub { die "timeout" };
      alarm($timeout);
      connect(SOCKET, $paddr) || error();
      alarm(0);
    };
    
    if ($@) {
      close SOCKET || warn "close: $!";
      # print "$hostname is NOT listening on tcp port $portnumber.\n";
      return 0;
    }
    else {
      close SOCKET || warn "close: $!";
      # print "$hostname is listening on tcp port $portnumber.\n";
      return 1;
    }
}

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How can I fix this...

OR

How can I detect if a port is in use?

-------------------------------------
Nothing is too wonderful to be true
-- Michael Faraday

In reply to Detecting a port "in use" on localhost:$port by freddo411

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